/**
 * Copyright (c) 2016-present, Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CAFFE2_UTILS_PROTO_UTILS_H_
#define CAFFE2_UTILS_PROTO_UTILS_H_

#ifdef CAFFE2_USE_LITE_PROTO
#include <google/protobuf/message_lite.h>
#else // CAFFE2_USE_LITE_PROTO
#include <google/protobuf/message.h>
#endif  // !CAFFE2_USE_LITE_PROTO

#include "caffe2/core/logging.h"
#include "caffe2/proto/caffe2.pb.h"

namespace caffe2 {

using std::string;
using ::google::protobuf::MessageLite;

// A wrapper function to return device name string for use in blob serialization
// / deserialization. This should have one to one correspondence with
// caffe2/proto/caffe2.proto: enum DeviceType.
//
// Note that we can't use DeviceType_Name, because that is only available in
// protobuf-full, and some platforms (like mobile) may want to use
// protobuf-lite instead.
std::string DeviceTypeName(const int32_t& d);

// Returns if the two DeviceOptions are pointing to the same device.
bool IsSameDevice(const DeviceOption& lhs, const DeviceOption& rhs);

// Common interfaces that reads file contents into a string.
bool ReadStringFromFile(const char* filename, string* str);
bool WriteStringToFile(const string& str, const char* filename);

// Common interfaces that are supported by both lite and full protobuf.
bool ReadProtoFromBinaryFile(const char* filename, MessageLite* proto);
inline bool ReadProtoFromBinaryFile(const string filename, MessageLite* proto) {
  return ReadProtoFromBinaryFile(filename.c_str(), proto);
}

void WriteProtoToBinaryFile(const MessageLite& proto, const char* filename);
inline void WriteProtoToBinaryFile(const MessageLite& proto,
                                   const string& filename) {
  return WriteProtoToBinaryFile(proto, filename.c_str());
}

#ifdef CAFFE2_USE_LITE_PROTO

inline string ProtoDebugString(const MessageLite& proto) {
  return proto.SerializeAsString();
}

// Text format MessageLite wrappers: these functions do nothing but just
// allowing things to compile. It will produce a runtime error if you are using
// MessageLite but still want text support.
inline bool ReadProtoFromTextFile(
    const char* /*filename*/,
    MessageLite* /*proto*/) {
  LOG(FATAL) << "If you are running lite version, you should not be "
                  << "calling any text-format protobuffers.";
  return false;  // Just to suppress compiler warning.
}
inline bool ReadProtoFromTextFile(const string filename, MessageLite* proto) {
  return ReadProtoFromTextFile(filename.c_str(), proto);
}

inline void WriteProtoToTextFile(
    const MessageLite& /*proto*/,
    const char* /*filename*/) {
  LOG(FATAL) << "If you are running lite version, you should not be "
                  << "calling any text-format protobuffers.";
}
inline void WriteProtoToTextFile(const MessageLite& proto,
                                 const string& filename) {
  return WriteProtoToTextFile(proto, filename.c_str());
}

inline bool ReadProtoFromFile(const char* filename, MessageLite* proto) {
  return (ReadProtoFromBinaryFile(filename, proto) ||
          ReadProtoFromTextFile(filename, proto));
}

inline bool ReadProtoFromFile(const string& filename, MessageLite* proto) {
  return ReadProtoFromFile(filename.c_str(), proto);
}

#else  // CAFFE2_USE_LITE_PROTO

using ::google::protobuf::Message;

inline string ProtoDebugString(const Message& proto) {
  return proto.ShortDebugString();
}

bool ReadProtoFromTextFile(const char* filename, Message* proto);
inline bool ReadProtoFromTextFile(const string filename, Message* proto) {
  return ReadProtoFromTextFile(filename.c_str(), proto);
}

void WriteProtoToTextFile(const Message& proto, const char* filename);
inline void WriteProtoToTextFile(const Message& proto, const string& filename) {
  return WriteProtoToTextFile(proto, filename.c_str());
}

// Read Proto from a file, letting the code figure out if it is text or binary.
inline bool ReadProtoFromFile(const char* filename, Message* proto) {
  return (ReadProtoFromBinaryFile(filename, proto) ||
          ReadProtoFromTextFile(filename, proto));
}

inline bool ReadProtoFromFile(const string& filename, Message* proto) {
  return ReadProtoFromFile(filename.c_str(), proto);
}

#endif  // CAFFE2_USE_LITE_PROTO

template <
    class IterableInputs = std::initializer_list<string>,
    class IterableOutputs = std::initializer_list<string>,
    class IterableArgs = std::initializer_list<Argument>>
OperatorDef CreateOperatorDef(
    const string& type,
    const string& name,
    const IterableInputs& inputs,
    const IterableOutputs& outputs,
    const IterableArgs& args,
    const DeviceOption& device_option = DeviceOption(),
    const string& engine = "") {
  OperatorDef def;
  def.set_type(type);
  def.set_name(name);
  for (const string& in : inputs) {
    def.add_input(in);
  }
  for (const string& out : outputs) {
    def.add_output(out);
  }
  for (const Argument& arg : args) {
    def.add_arg()->CopyFrom(arg);
  }
  if (device_option.has_device_type()) {
    def.mutable_device_option()->CopyFrom(device_option);
  }
  if (engine.size()) {
    def.set_engine(engine);
  }
  return def;
}

// A simplified version compared to the full CreateOperator, if you do not need
// to specify args.
template <
    class IterableInputs = std::initializer_list<string>,
    class IterableOutputs = std::initializer_list<string>>
inline OperatorDef CreateOperatorDef(
    const string& type,
    const string& name,
    const IterableInputs& inputs,
    const IterableOutputs& outputs,
    const DeviceOption& device_option = DeviceOption(),
    const string& engine = "") {
  return CreateOperatorDef(
      type,
      name,
      inputs,
      outputs,
      std::vector<Argument>(),
      device_option,
      engine);
}

bool HasOutput(const OperatorDef& op, const std::string& output);
bool HasInput(const OperatorDef& op, const std::string& input);

/**
 * @brief A helper class to index into arguments.
 *
 * This helper helps us to more easily index into a set of arguments
 * that are present in the operator. To save memory, the argument helper
 * does not copy the operator def, so one would need to make sure that the
 * lifetime of the OperatorDef object outlives that of the ArgumentHelper.
 */
class ArgumentHelper {
 public:
  template <typename Def>
  static bool HasArgument(const Def& def, const string& name) {
    return ArgumentHelper(def).HasArgument(name);
  }

  template <typename Def, typename T>
  static T GetSingleArgument(
      const Def& def,
      const string& name,
      const T& default_value) {
    return ArgumentHelper(def).GetSingleArgument<T>(name, default_value);
  }

  template <typename Def, typename T>
  static bool HasSingleArgumentOfType(const Def& def, const string& name) {
    return ArgumentHelper(def).HasSingleArgumentOfType<T>(name);
  }

  template <typename Def, typename T>
  static vector<T> GetRepeatedArgument(
      const Def& def,
      const string& name,
      const std::vector<T>& default_value = std::vector<T>()) {
    return ArgumentHelper(def).GetRepeatedArgument<T>(name, default_value);
  }

  template <typename Def, typename MessageType>
  static MessageType GetMessageArgument(const Def& def, const string& name) {
    return ArgumentHelper(def).GetMessageArgument<MessageType>(name);
  }

  template <typename Def, typename MessageType>
  static vector<MessageType> GetRepeatedMessageArgument(
      const Def& def,
      const string& name) {
    return ArgumentHelper(def).GetRepeatedMessageArgument<MessageType>(name);
  }

  explicit ArgumentHelper(const OperatorDef& def);
  explicit ArgumentHelper(const NetDef& netdef);
  bool HasArgument(const string& name) const;

  template <typename T>
  T GetSingleArgument(const string& name, const T& default_value) const;
  template <typename T>
  bool HasSingleArgumentOfType(const string& name) const;
  template <typename T>
  vector<T> GetRepeatedArgument(
      const string& name,
      const std::vector<T>& default_value = std::vector<T>()) const;

  template <typename MessageType>
  MessageType GetMessageArgument(const string& name) const {
    CAFFE_ENFORCE(arg_map_.count(name), "Cannot find parameter named ", name);
    MessageType message;
    if (arg_map_.at(name).has_s()) {
      CAFFE_ENFORCE(
          message.ParseFromString(arg_map_.at(name).s()),
          "Faild to parse content from the string");
    } else {
      VLOG(1) << "Return empty message for parameter " << name;
    }
    return message;
  }

  template <typename MessageType>
  vector<MessageType> GetRepeatedMessageArgument(const string& name) const {
    CAFFE_ENFORCE(arg_map_.count(name), "Cannot find parameter named ", name);
    vector<MessageType> messages(arg_map_.at(name).strings_size());
    for (int i = 0; i < messages.size(); ++i) {
      CAFFE_ENFORCE(
          messages[i].ParseFromString(arg_map_.at(name).strings(i)),
          "Faild to parse content from the string");
    }
    return messages;
  }

 private:
  CaffeMap<string, Argument> arg_map_;
};

const Argument& GetArgument(const OperatorDef& def, const string& name);
bool GetFlagArgument(
    const OperatorDef& def,
    const string& name,
    bool def_value = false);

Argument* GetMutableArgument(
    const string& name,
    const bool create_if_missing,
    OperatorDef* def);

template <typename T>
Argument MakeArgument(const string& name, const T& value);

template <typename T>
inline void AddArgument(const string& name, const T& value, OperatorDef* def) {
  GetMutableArgument(name, true, def)->CopyFrom(MakeArgument(name, value));
}

bool inline operator==(const DeviceOption& dl, const DeviceOption& dr) {
  return IsSameDevice(dl, dr);
}

} // namespace caffe2

namespace std {
template <>
struct hash<caffe2::DeviceOption> {
  typedef caffe2::DeviceOption argument_type;
  typedef std::size_t result_type;
  result_type operator()(argument_type const& device_option) const {
    std::string serialized;
    CAFFE_ENFORCE(device_option.SerializeToString(&serialized));
    return std::hash<std::string>{}(serialized);
  }
};
} // namespace std

#endif // CAFFE2_UTILS_PROTO_UTILS_H_
